Ceramic-ceramic composites are known where the matrix reinforced with silicon carbide fibers is lithia-aluminosilicate, alumina, silicon nitride, zirconia, molybdenum disilicide, or lead zirconium titanate, etc.
While these materials by in large have suitable strengths both at ambient and at high temperatures, some applications are benefited by high strengths at ambient up to 1000.degree. C. and higher but also higher strengths than have heretofore been obtained with many ceramic-ceramic composites at temperatures on the order of 1200.degree. C.-1300.degree. C.
Ceramic parts are normally fabricated from ceramic-ceramic composites by hot pressing a loose powder (with silicon carbide fibers uniformly distributed therein) into pancake or billet form and then machining to final form. In hot pressing, the loose powder may not densify uniformly, and this leads to poor uniformity in strength in products produced therefrom. Furthermore, hot pressing is only carried out in closed die which requires precise control of the amount of material being fabricated.